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參數(shù)資料
| 型號(hào)： | LTC4274CIUHF#PBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 電源管理 |
| 英文描述： | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
| 封裝： | 7 X 5 MM, LEAD FREE, PLASTIC, MO-220WHKD, QFN-38 |
| 文件頁數(shù)： | 8/28頁 |
| 文件大?。?/td> | 313K |
| 代理商： | LTC4274CIUHF#PBF |
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LTC4274A/LTC4274C
16
4274acf
operAtion
When a PD is detected, the PSE optionally looks for a
classification signature that tells the PSE the maximum
power the PD will draw. The PSE can use this information
to allocate power among several ports, police the current
consumption of the PD, or to reject a PD that will draw
more power that the PSE has available. For a 802.3af PSE,
the classification step is optional; if a PSE chooses not to
classify a PD, it must assume that the PD is a 13W (full
802.3af power) device.
New in 802.3at
Thenewer802.3atstandardsupersedes802.3afandbrings
several new features:
APDmaydrawasmuchas25.5W.SuchPDs(andthe
PSEs that support them) are known as Type 2. Older
13W 802.3af equipment is classified as Type 1. Type 1
PDs will work with all PSEs; Type 2 PDs may require
Type2PSEstoworkproperly.TheLTC4274A/LTC4274C
is designed to work in both Type 1 and Type 2 PSE de-
signs, and also supports non-standard configurations
at higher power levels.
TheClassificationprotocolisexpandedtoallowType2
PSEs to detect Type 2 PDs, and to allow Type 2 PDs to
determine if they are connected to a Type 2 PSE. Two
versions of the new Classification protocol are avail-
able: an expanded version of the 802.3af Class Pulse
protocol, and an alternate method integrated with the
existing LLDP protocol (using the Ethernet data path).
The LTC4274A/LTC4274C fully supports the new Class
Pulse protocol and is also compatible with the LLDP
protocol(whichisimplementedinthedatacommunica-
tions layer, not in the PoE circuitry).
Faultprotectioncurrentlevelsandtimingareadjusted
to reduce peak power in the MOSFET during a fault;
this allows the new 25.5W power levels to be reached
using the same MOSFETs as older 13W designs.
Extended Power LTPoE++
TheLTC4274Aaddsthecapabilitytoautonomouslydeliver
up to 90W of power to the PD. LTPoE++ PDs may forgoe
802.3 LLDP support and rely solely on the LTPoE++ Physi-
cal Classification to negotiate power with LTPoE++ PSEs;
this greatly simplifies high-power PD implementations.
LTPoE++ classification may be optionally enabled for the
LTC4274A by setting both the High Power Enable and
LTPoE++ Enable bits.
The higher levels of LTPoE++ delivery impose additional
layoutandcomponentselectionconstraints.TheLTC4274A
is offered in four power levels (-1, -2, -3, and -4) which
allows the AUTO pin mode LTC4274A to autonomously
power up to supported power levels. If the AUTO pin is
high, internal circuitry determines the maximum deliver-
able power. PDs requesting more than the available power
limits are not powered.
Table 1. LTPoE++ Auto Pin Mode Maximum Delivered
Power Capabilities
PART
PAIRS
PD POWER
LTC4274A-1
2
35W
LTC4274A-2
2
45W
LTC4274A-3
4
70W
LTC4274A-4
4
90W
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC4274AIUHF-4#TRPBF | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
| LTC4274AIUHF-3#PBF | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
| LTC4274AIUHF-2#TRPBF | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
| LTC4274AIUHF-2#PBF | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
| LTC4274AIUHF-1#TRPBF | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC4274CUHF#PBF | 功能描述:IC CONTROLLER POE 38-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:119 系列:- 類型:熱交換控制器 應(yīng)用:通用型，PCI Express? 內(nèi)部開關(guān):無 電流限制:- 電源電壓:3.3V，12V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:80-TQFP 供應(yīng)商設(shè)備封裝:80-TQFP（12x12） 包裝:托盤 產(chǎn)品目錄頁面:1423 (CN2011-ZH PDF) |
| LTC4274CUHF#TRPBF | 制造商:Linear Technology 功能描述:POE Controller 25.5W 38-Pin QFN EP |
| LTC4274IUHF#PBF | 制造商:Linear Technology 功能描述:POE Controller 25.5W 38-Pin QFN EP 制造商:Linear Technology 功能描述:Bulk 制造商:Linear Technology 功能描述:IC POE IEEE 802.3AT 38-QFN 制造商:Linear Technology 功能描述:IC POE CNTRL 38QFN 制造商:Linear Technology 功能描述:IC, POE, CNTRL, 38QFN 制造商:Linear Technology 功能描述:IC, POE CONTROLLER, 3.6V, QFN-38; Input Voltage:3.6V; Supply Current:1.1mA; Digital IC Case Style:QFN; No. of Pins:38; Frequency:1MHz; Operating Temperature Min:-40C; Operating Temperature Max:85C; MSL:MSL 1 - Unlimited ;RoHS Compliant: Yes |
| LTC4274IUHF#PBF | 制造商:Linear Technology 功能描述:IC POE CONTROLLER 3.6V QFN-38 |
| LTC4274IUHF#TRPBF | 制造商:Linear Technology 功能描述:POE Controller 25.5W 38-Pin QFN EP |
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